Strip coiling by carousel tension coils, which will more simply be called carousel coiling, is well known as a system for final coiling in continuous rolling, both in a cold rolling mill and a hot rolling mill.
The coiling sequence is as follows:                the carousel is in the receiving position with the raised belt winder around mandrel no. 1 in the lower position, the free mandrel no. 2 being in the upper position at 180°;        once the strip is primed, the belt winder retracts and the coiling of coil no. 1 continues;        while the coiling continues, the entire carousel rotates 180° clockwise if the strip comes from the left (otherwise in the opposite direction), which places coil no. 1 undergoing coiling in the evacuation position and the free mandrel in the receiving position for the front end of the next strip to be coiled;        at the end of coiling of coil no. 1, the power is transferred to mandrel no. 2. Coil no. 1 is evacuated and the next coiling cycle begins.        
The embodiment details of the means making up the coiling carousel such as the belt winder, the position of the mandrels, the mandrel support and evacuation device, etc. are well known by those skilled in the art.
One problem that arises is that of detecting, as early as possible in the manufacturing method, the faults that may be crippling for the rolled strip, for example faults of surface, geometry, thickness, flatness, etc. A separate inspection of the line cannot be contemplated, as it is disadvantageous in terms of lost time and hence from an economic standpoint.
Document JP 2000 254725 discloses a cold rolling installation comprising, mounted in that order on the line, a cold rolling mill, a moving shears that cuts the steel strip continuously produced by the rolling mill, a double-mandrel tension coiling apparatus, of the carousel winder type, which continuously coils the steel strip. The carousel coiler is positioned downstream from and below the passing line of the cold rolling mill, and a surface-inspection apparatus that inspects the surface of the steel strip is situated downstream on an extension of the passing line that passes above the carousel coiler. The installation is provided with orienting means to direct the strip toward the carousel winder or, alternatively, toward the surface-inspection apparatus, which are positioned outside the moving shears.
Document EP 1 581 355 discloses a method for the successive rolling and coiling of a metal strip, in particular a steel strip, on a coiling mandrel that is rotated and capable of being moved away, in which the metal strip is inspected in longitudinal portions relative to rolling anomalies. The strip specimens are produced by a drum shears located after the last rolling stand, guided and stopped “on-line” inside the rolling line above a coiling station situated below the rolling line, on an inspection table, for a free visual inspection.
The coiling station is therefore situated under the plane of the inspection table, the latter being positioned “on-line” with the rolling line. Here again, the steel strip that emerges from the last rolling stand may be guided such that a deflecting unit, arranged at the input of the coiling station, can deflect the metal strip toward a coiling mandrel.
Generally, the inspection table is provided with gripping means that allow to turn the strip specimens over in order to inspect the other face as well.
Furthermore, after the inspection on the inspection table, the strip specimens are conveyed toward a shears that reduces them to pieces before they are collected by gravity in a waste tub or cart.
The above-described solutions have advantages over a separate off-line inspection: short access time and fast inspection, use of only one specimen of the strip and therefore no need to remove an entire coil from the material flow. They do, however, have the drawbacks of using an orienting system or deflector.